On 64-bit machines, PCI_BASE_ADDRESS_MEM_MASK and other mask constants
passed to pci_size() are 64-bit (for example ~0x0fUL). However, pci_size
does comparisons between the u32 arguments and the mask, which will fail
even though any result from pci_size is still just 32-bit.

Changing the mask argument to u32 seems the obvious thing to do, since all
arithmetic in the function is 32-bit and having a larger mask makes no
sense.

This triggered on a PPC64 system here where an adapter (VGA, as it
happened) had a memory region base of 0xfe000000 and a sz of the same,
matching the if (max == maxbase ...) test at the bottom of pci_size but
failing the mask comparison. Quite a corner case which I guess explains
why we haven't seen it until now.

This patch alows you to change the source address of icmp error
messages. It applies cleanly to 2.6.11.11 and retains the default
behaviour.

In the old (default) behaviour icmp error messages are sent with the ip
of the exiting interface.

The new behaviour (when the sysctl variable is toggled on), it will send
the message with the ip of the interface that received the packet that
caused the icmp error. This is the behaviour network administrators will
expect from a router. It makes debugging complicated network layouts
much easier. Also, all 'vendor routers' I know of have the later
behaviour.

Userland layer-2 tunneling devices allocated through the TUNTAP driver
(drivers/net/tun.c) have a type of ARPHRD_NONE, and have no link-layer
address. The kernel complains at regular interval when IPv6 Privacy
extension are enabled because it can't find an hardware address :

IPv6 Privacy extensions should probably be disabled on that sort of
device. They won't work anyway. If userland wants a more usual
Ethernet-ish interface with usual IPv6 autoconfiguration, it will use a
TAP device with an emulated link-layer and a random hardware address
rather than a TUN device.

As far as I could fine, TUN virtual device from TUNTAP is the very only
sort of device using ARPHRD_NONE as kernel device type.